An Afghan family walks in the old part of Herat on December 23, 2012. Over a third of Afghans are living in abject poverty, as those in power are more concerned about addressing their vested interests rather than the basic needs of the population, a UN report said.

The female police officer who shot dead a US civilian adviser working for NATO in Afghanistan has been identified as an Iranian national, CNN reported Tuesday.

The woman killed the contractor in the Kabul police headquarters early Monday morning, CNN reported, in what is being called the first insider attack by a female.

According to the Wall Street Journal, Afghan Interior Ministry spokesman Sediq Sediqqi told reporters Tuesday that the woman, identified by Afghan authorities as Nargis, is an Iranian national married to an Afghan man.

The Australian Associated Press cited Kabul's Deputy Police Chief Mohammad Daoud Amin as saying an investigation was under way to determine whether the killing was intentional or accidental.

More than 50 coalition personnel have been killed this year in insider attacks by Afghan soldiers, police or those dressed like them, the WSJ said.

In a separate incident, at least six local policemen were killed by man in an officer's uniform in northern Afghanistan.

The Iranian woman is being described as a female officer who came looking for the police chief at the heavily secured headquarters in Kabul.

The woman, who is in custody and will face prosecution in an Afghan court, may have had links with the Taliban, officials said.

According to the BBC, the US adviser may have been on his way to a canteen when the woman drew a pistol and shot him.